Degradable cellulose ester

Abstract

Disclosed herein is a degradable cellulose ester. The cellulose ester may be formed into tow for use in cigarette filters or into articles, such as molded articles. A basic material, an enzymatic material, or combinations thereof is included in the cellulose ester in order to degrade the cellulose ester.

We claim: 
     
       1. A degradable cigarette filter comprising:
 a filter element comprising bloomed cellulose acetate tow, wherein the cellulose acetate has a degree of substitution (DS) of greater than 1.3; 
 a pill dispersed in the bloomed cellulose acetate tow; and 
 a plug wrap at least partially surrounding the filter element; 
 wherein the pill comprises a coating and at least one of a basic material, an enzymatic material, or a combination thereof, 
 wherein the coating comprises at least 1 wt. % of the basic material, at least 1 wt. % of the enzymatic material, or a combination thereof, based on the total weight of the coating; and 
 wherein the pill, when exposed to water, deacetylates the bloomed cellulose acetate tow by at least 10% in 20 days or less. 
 
     
     
       2. The filter of  claim 1 , wherein the water solubility of the basic material is less than the water solubility of the coating. 
     
     
       3. The filter of  claim 2 , wherein the basic material comprises at least one of calcium oxide, calcium hydroxide, magnesium hydroxide, magnesium oxide, or combinations thereof. 
     
     
       4. The filter of  claim 2 , wherein the pill comprises a basic material and an enzymatic material, and wherein the enzymatic material comprises an esterase, a cellulase, a glucosidase, or combinations thereof. 
     
     
       5. The filter of  claim 2 , wherein the enzymatic material comprises an esterase. 
     
     
       6. The filter of  claim 2 , wherein the coating has a thickness from 0.1 to 100 μm. 
     
     
       7. A degradable cellulose acetate tow, wherein the cellulose acetate tow has a degree of substitution of greater than 1.3 and wherein the cellulose acetate tow further comprises a pill dispersed in the cellulose acetate tow, wherein the pill comprises a coating and at least one of a basic material, an enzymatic material, or a combination thereof, wherein the coating comprises at least 1 wt. % of the basic material, at least 1 wt. % of the enzymatic material, or a combination thereof, based on the total weight of the coating; and wherein the pill, when exposed to water, deacetylates the cellulose acetate tow by at least 10% in 20 days or less. 
     
     
       8. The tow of  claim 7 , wherein the water solubility of the basic material is less than the water solubility of the coating. 
     
     
       9. The tow of  claim 7 , wherein the basic material comprises at least one of calcium oxide, calcium hydroxide, magnesium hydroxide, magnesium oxide, or combinations thereof. 
     
     
       10. The tow of  claim 7 , wherein the pill comprises a basic material and an enzymatic material, and wherein the enzymatic material comprises an esterase, a cellulase, a glucosidase, or combinations thereof. 
     
     
       11. The tow of  claim 7 , wherein the enzymatic material comprises an esterase. 
     
     
       12. The tow of  claim 7 , wherein the coating has a thickness from 0.1 to 100 μm.